package com.hmdp.service.impl;

import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONObject;
import cn.hutool.json.JSONUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.Shop;
import com.hmdp.mapper.ShopMapper;
import com.hmdp.service.IShopService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.CacheChlient;
import com.hmdp.utils.RedisData;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import static com.hmdp.utils.RedisConstants.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class ShopServiceImpl extends ServiceImpl<ShopMapper, Shop> implements IShopService {
@Resource
private StringRedisTemplate stringRedisTemplate;
@Resource
private CacheChlient cacheChlient;

    @Override
    public Result queryById(Long id) {
        //缓存穿透
       // Shop shop=cacheChlient.queryWiterPassThrough(CACHE_SHOP_KEY,id,Shop.class,this::getById,CACHE_SHOP_TTL,TimeUnit.MINUTES);
       // Shop shop=queryWiterPassThrough(id);
        //互斥锁解决缓存击穿
         //Shop shop=queryWithMutex(id);
        //逻辑过期解决缓存击穿
        //Shop shop=queryWithLogiclExpire(id);
        Shop shop=cacheChlient.queryWithLogiclExpire(CACHE_SHOP_KEY,id,Shop.class,this::getById,CACHE_SHOP_TTL,TimeUnit.MINUTES);
if(shop==null){
    return Result.fail("店铺不存在");
}
//返回
return  Result.ok(shop);
    }


    /*public Shop queryWithMutex(Long id) {
        String key = CACHE_SHOP_KEY + id;
//从redis查询商铺缓存
        String shopJson = stringRedisTemplate.opsForValue().get(key);
        //判断是否存在
        if (StrUtil.isNotBlank(shopJson)) {

            return JSONUtil.toBean(shopJson, Shop.class);
        }
        if (shopJson != null) {
            //返回一个错误信息
            return null;
        }
//4 实现缓存重建
//4.1获取互斥锁

        String locaKey = "lock:shop:" + id;
        Shop shop;
        try {
            boolean isLock = tryLocake(locaKey);
//4.2判断是否获取成功
            if (!isLock) {
                Thread.sleep(50);
                return queryWithMutex(id);
            }
//4.3失败，休眠并重试
//4.4成功，根据id查询数据库
            //
            Thread.sleep(200);
            shop = getById(id);
            if (shop == null) {
                //将空值写入redis
                stringRedisTemplate.opsForValue().set(key, "", CACHE_NULL_TTL, TimeUnit.MINUTES);
                //数据库不存在，返回错误
                return null;
            }

            //存在写入redis
            stringRedisTemplate.opsForValue().set(key, JSONUtil.toJsonStr(shop), CACHE_SHOP_TTL, TimeUnit.MINUTES);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        } finally {

            //释放锁
            unlock(locaKey);
        }
        //返回
        return shop;
    }*/


/* public Shop queryWiterPassThrough(Long id){
     String key=CACHE_SHOP_KEY+id;
//从redis查询商铺缓存
     String shopJson=   stringRedisTemplate.opsForValue().get(key);
     //判断是否存在
     if(StrUtil.isNotBlank(shopJson)){

         return JSONUtil.toBean(shopJson,Shop.class);
     }
     if(shopJson!=null){
         //返回一个错误信息
         return null;
     }

     Shop shop=getById(id);
     //不存在，根据id查询数据库
     if(shop==null){
         //将空值写入redis
         stringRedisTemplate.opsForValue().set(key,"",CACHE_NULL_TTL, TimeUnit.MINUTES);
         //数据库不存在，返回错误
         return null;
     }

     //存在写入redis
     stringRedisTemplate.opsForValue().set(key,JSONUtil.toJsonStr(shop),CACHE_SHOP_TTL, TimeUnit.MINUTES);
     //返回
     return shop;
 }*/
private static final ExecutorService CACHE_REBUILD_EXECUTO= Executors.newFixedThreadPool(10);
    /*public Shop queryWithLogiclExpire(Long id){
        String key=CACHE_SHOP_KEY+id;
//从redis查询商铺缓存
        String shopJson=   stringRedisTemplate.opsForValue().get(key);
        //判断是否存在
        if(StrUtil.isBlank(shopJson)){

            return null;
        }
        //命中，需要把JSON反序列化为对象
        //RedisData redisData = JSONUtil.toBean(shopJson.RedisData.class);
          RedisData redisData = JSONUtil.toBean(shopJson, RedisData.class);
         JSONObject data= (JSONObject) redisData.getData();
        //判断是否过期

        //未过期，直接返回商铺信息
        //已过期，缓存重建
        //获取互斥锁
        //判断获取成功
        //成功，开启独立线程，实现缓存重建
        //返回过期商铺信息
        //不存在，根据id查询数据库

        Shop shop=getById(id);
        //不存在，根据id查询数据库
        if(shop==null){
            //将空值写入redis
            stringRedisTemplate.opsForValue().set(key,"",CACHE_NULL_TTL, TimeUnit.MINUTES);
            //数据库不存在，返回错误
            return null;
        }

        //存在写入redis
        stringRedisTemplate.opsForValue().set(key,JSONUtil.toJsonStr(shop),CACHE_SHOP_TTL, TimeUnit.MINUTES);
        //返回
        return shop;
    }
*/







//获取锁
/*
private boolean tryLocake(String key){
       Boolean flag= stringRedisTemplate.opsForValue().setIfAbsent(key,"1",10, TimeUnit.SECONDS);
     return BooleanUtil.isTrue(flag);
}
//释放锁
private void unlock(String key){
        stringRedisTemplate.delete(key);
}
*/

public void saveShop2Redis(Long id,Long expireSeconds){
        //查询店铺数据
    Shop shop=getById(id);
    //封装逻辑过期时间
    RedisData redisData=new RedisData();
    redisData.setData(shop);
    redisData.setExpireTime(LocalDateTime.now().plusSeconds(expireSeconds));
    //写入redis
    stringRedisTemplate.opsForValue().set(CACHE_SHOP_KEY+id,JSONUtil.toJsonStr(redisData));

}














    @Override
    @Transactional
    public Result updata(Shop shop) {
       Long id=shop.getId();
       if(id==null){
           return Result.fail("店铺id不能为空");
       }
         //更新数据库
updateById(shop);
        //删除缓存
stringRedisTemplate.delete(CACHE_SHOP_KEY+id);



        return null;
    }
}
